Support is requested for continued investigations of applications of Fourier transform mass spectrometry to analysis of non-volatile biomolecules with masses in the range of 2,000 to 100,000 daltons or higher. A principle emphasis of the research will be further development of the new technique of high resolution matrix-assisted laser desorption (MALDI) to allow its application to bioanalytical problems previously impossible to investigate by mass spectrometry. The research will utilize an Extrel 7.2 Tesla FTMS dual cell instrument and a 3 Tesla Nicolet FTMS- 1000 single cell instrument recently converted for laser desorption operation. Instrumental and methodological developments to be explored include: investigation of a new 5-plate gated trapping procedure for use in MALDI applications; examination of a new laser desorption geometry, desorbing materials normal, rather than parallel, to the magnetic field axis; development of quadripolar axialization of high mass ions in conjunction with MALDI; addition of a high performance rapid switching trapping module for use in both axialization and surface-induced dissociation experiments. Sample-preparation and analytical application studies will: further examine the use of mixed MALDI matrices and the effects of matrix composition on MALDI of high mass molecules; investigate sample preparation methods intended to produce multiply-charged ions by MALDI, with the goal of achieving some of the mass range and resolution advantages that would allow; explore application of MALDI-FTMS to categories of compounds other than proteins, such as nucleotides, nucleosides, and oligosaccharides; and improve methods for off-line MALDI of capillary electrophoresis effluents. Fundamentals of MALDI also will be studied with the aim of understanding the factors governing the process. These studies are expected to be of substantial assistance in designing efficacious new techniques for bioanalytical applications.